Do you ever feel like your heart is racing or fluttering, even when you're sitting still? If so, you may have atrial fibrillation. RA is linked to an increased risk of heart disease, including atrial fibrillation, but a new study raises some questions about this link.
What is Atrial Fibrillation?
A healthy heart beats between 60 and 90 times a minute when at rest. As you may have noticed in yourself (or from TV shows), the heart has a one-two rhythm when it beats or contracts, sort of a da-dum, da-dum, da-dum. The first part happens with the two upper chambers (atria) contract slightly before the two lower chambers (ventricles) contract. In atrial fibrillation, this regular rhythm is interrupted. The atria beats faster or more irregularly, up to 500 times a minute and the ventricle up to 180 times. That's pretty uncomfortable. It can also be dangerous. If left untreated, people who have atrial fibrillation are five times more likely to have a stroke and may be at risk for heart failure.
Atrial fibrillation can be caused by a number of different conditions, including heart disease, excessive alcohol consumption, and systemic conditions such as hyperthyroidism and diabetes. It can also occur with no underlying cause. It is the most common cardiac arrhythmia, affecting almost three million people in the US.
Atrial fibrillation can be treated with a number of different types of medication, as well as lifestyle modifications. It can also be treated with a procedure called cardioversion, in which electrical stimulation can shock the heart back into a normal rhythm. More serious cases may require surgical intervention.
Atrial Fibrillation Linked to RA
That RA needs an increased risk of heart attack and stroke has been well known for many years. However, that people with RA are more likely to experience atrial fibrillation is a relatively recent discovery. A Danish longitudinal study showed that people with RA are 40 percent more likely to have atrial fibrillation, whereas a 2011 study showed a 60 percent increased risk.
Why the difference? The Danish study used data from the entire Danish population, whereas the 2011 study used hospital data. It's possible that the sources of data might have influenced the results. Nonetheless, research seemed seems to indicate that even when adjusting for factors such as comorbidities (e.g. existing heart disease), people with RA had an increased risk of developing atrial fibrillation. It was theorized that systemic RA inflammation which can contribute to other forms of cardiovascular disease, also contributed to the development of atrial fibrillation.
New Study Shows No Link
A new study by Seoyoung et.al. investigated the link between systemic inflammation and atrial fibrillation by comparing hospitalizations for people with RA and a control group. The researchers adjusted the results for comorbidities, demographic factors, and medication. Once the data had been adjusted to eliminate the influence of these other contributing factors, the results did not show an association between atrial fibrillation and RA.
The researchers suggested several factors that could explain this lack of a link. The data was acquired from a large commercial health plan and everyone in the RA group were being treated with DMARDs (disease modifying antirheumatic drugs). It's quite likely that this lowered their systemic inflammation. Another possible explanation was that RA is linked to atrial fibrillation through other factors, such as cardiovascular disease and use of NSAIDs or steroids.
What This Means for You
So is there a causal link between RA and atrial fibrillation and if so, what causes it? This appears to be a developing part of the literature. More research is necessary to get more clarity on exactly what's going on.
The next question is should you worry? Not necessarily. It's important to stay on top of all aspects of your health, something which can at times get lost under the focus of on your RA. Talk to your doctor about some of the comorbidities related to RA, such as heart health. In addition to staying on top of risk factors for heart attack and stroke, you may also want to want to discuss screening for atrial fibrillation with your doctor. If you develop symptoms of rapid or fluttering heartbeat, shortness of breath, dizziness or chest pains, go to the ER.
The new study by Seoyoung may be further supportive evidence of the importance of treating your RA. Previous research has shown that your risk of heart attack and stroke can be decreased by treating your RA with DMARDs or Biologics. The Seoyoung study suggested that treatment which reduces inflammation may also reduce factors that can lead to the development of atrial fibrillation.